Observation instrument



Jime1 7, 1930. HTEPH N 1,763,827

OBSERVATION INSTRUMENT Filed June 14, 1928 2 Sheets-Sheet l I 5 J WPF/GZ V 25 4 25 v M/Vf/W'fi/F I JJZEP/ILW June 1.7, 1930. J. STEPHEN1,763,827

OBSERVATION INSTRUMENT 7 Filed June-l4, 1928 2 Sheets-Sheet 2 //VVINTOR.

J. STEPHEN Patented June 1'7, 1930 UNITED STATES PATENT OFFICE JAMESSTEPHEN, OEE TORONTO, ONTARIO, CANADA, ASSIGNOR OF SIXTY PER GENT TOCAROLYNE HARWOOD QUIPP, F TORONTO, CANADA OBSERVATION INSTRUMENTApplication filed June 14,

My invention relates to improvements in observation instruments, and theobject of the invention is to devise a device whereby any local time maybe found and by which the latitude and longitude of the locality atwhich the observation is taken may be derived from calculations based onthe standard time and the found local time, and it consists essentiallyof the arrangement and construe tion of parts as hereinafter moreparticularly explained.

Fig. 1 is a perspective view of my device looking from the operativeside of the instrument or from the side on which the observation istaken.

Fig. 2 is a similar view to Fig. 1 looking at the reverse side.

Fig. 3 is a cross sectional view through the instrument taken from backto front.

In the drawings like characters of refer ence indicate correspondingparts in each figure.

1 indicates a bowl adapted to contain mercury, spirits or other suitablefluid upon wh ch 2 a disc 2 floats upon which the observation instrumentis carried so that it will automatlcallv level itself in any position inwhich it is placed. 3 and 4 are standard frames suitably secured to thedisc 2 and extending upward therefrom in a spaced position and providedwith inwardly extending opposing pointed pintles 5 and 6. 7 is acylinder provided with bearing recesses 7*, at diametrically oppositepoints in whlch the pointed ends of the pintles 5 and 6 engage so as toswingably support the cylinder so that its axis may be readily adjustedto any angular position. 8 and 9 are annular members surrounding thecylinder 7 adjacent its front and rear end and held in place by flanges10 and 11 so that such annular members may be turned to any desiredposition.

The annular member 8 is provided with an operating handle 8 by which theannular member 8 is turned circumt'erentially to any desired position.

12 is a tube which is supported centrally within the cylinder 7 at aslight angle to its axis as will hereinafter be explained. The

tube is supported by arms 13 connecting the 1928. Serial No. 285,383.

same to the annular member 8 and by arms 1-4 connecting the tube to theannular member 9.

It will thus be seen that when the handle 8* is operated the annularmember 8, tube 12, arms 13 and 1 1 and ring 9 will turn as one unit.

At the inner side of annular member 8 is turnably supported an annulartime disc 15 turnable around the cylinder 7.

16 is a calendar disc which is similar to the disc 15and turnablysupported upon the cylinder 7 and held against the disc 15 and in placefrom longitudinal movement by a flange Each half of the time disc 15 isdivided into 12 hours as will be clearly seen upon referring to Fig. 2,each of the hour spaces being divided into 5 minute spaces.

It may be pointed out that there are 365 days in the year. 7

The disc 16 is divided into 73 spaces each space approximating a 5 dayspace and these spaces are divided into series in proportion to thenumber of days in each month of the year such as in January 31 days,February 28 days, March 31 days, etc.

17 is a stationary pointer carried by the cylinder 7 and coacting withthe calendar disc 16.. The calendar disc 16 is provided with a lugextending radially therefrom as indicated at 18. 19 is a lug extendingfrom the time disc 15 and provided with a circumferential slot 20.

21 is a set screw extending through the slot 20 into the lug 18 so thatthe lugs 18 and I 19 may be locked together and the time disc 15 andcalendar disc 16 in the position desired as will hereinafter appear.

22 is a radial slot which may be formed in an enlargement of one of thearms 13 or in a separate arm attached to the annular meniber 8. Thisportion is also provided with a pointer 23 which coacts with the timedisc 15. 24 is a supplemental longitudinally slotted member attached tothe annular member' 8 on the lower portion thereof for a purpose whichwill hereinafter appear.

25 is a pointer carried by the cylinder 7 and extending radiallytherefrom and coacting with the stationary graduated scale 26 carried bythe floating disc 2, the scale 26 being divided from naught to ninety.

Having described the principal parts involved in my invention I willbriefly describe the operation of the same.

In order to set up the instrument the calendar disc is set at May 10thand the time disc to 9 hours, 23 minutes, which is the position in whichthe Alpha Star is at its meridian that is, directly above the North Starand will be observed at that particular day and hour through the slot 22of the device when so set.

It may also be pointed out that the tube 12 is set at a slight angle tothe true axis of the cylinder 7, the angle between the axis of thecylinder and the axis of the tube being 1 degree and 5 minutes(corresponding to the distance that the North Star is off centre)towards 1 hour and minutes on the time disc which indicates the stellartime at which the North Star reaches its meridian. The stellar time of(lassiopeias for-most star hereinafter reterred is hours minutes, NorthStar 1 hour 36 minutes and Ursa Major hours 59 minutes. These starspractically always maintain the aforesaid relation in all positions theamount of variation being infinitessimal.

In order to find the local time at any position on the earths surfacethe observer looks through the tube so as to observe the North Startherethrough. The handle 8 is then operated so as to turn the angularmember 8 and the parts connected thereto circumterenti ally until thefirst star Alpha of the constellation Ursa Major commonly known as thedipper is seen through the slot 22. The pointer 23 will then indicatethe correct time on the time disc 15.

In order to obtain the standard time of any place in which the observeris located, knowing that the earth turns 1 degree in 4; n'iinutes, andthe longitude reading is multiplied by et and then divided into hoursand minutes in the usual way.

From the local time found as above described and the standard timecorresponding to Greenwich time which would be indicated by theobservers watch the longitude of the locality can then be obtained. Thenumber of minutes difference between the standard. and local. time isdivided by 4, thus giving the number of longitude degrees. There isadifierence of 4 minutes between each degree, and by this means theexact longitude of any particular place is obtained.

In order to find the latitude all that the observer has to do is toswing the instrument on its t *ansverse axis formed by the pintles 5 and6 until the North Star is observed through the tube 12, which isinclined as before set forth at angle of 1 5' to its true axis. Thepointer 25 will then indicate on the scale 18 a true reading of thenumber of latitude degrees.

hen the Alpha Star is below the horizon the foremost star of theconstellation Cassiopeia is used, this star being observed through thelongitudinally slotted member 24, the device being then operated in thesame way as above described.

At the end of each year the calendar disc is disengaged from the timedisc and moved up a distance of a quarter day in order to take care ofthe extra six hours in the year. At leap year the calendar is moved backa day on February 28th, in order to compensate for the extra day.

What I claim as my invention is 1. An observation instrument comprisinga cylindrical member, a pair of annular disc members surrounding thecylinder, the exposed face of one member being graduated into hours andminutes and the exposed face of the other member into months and days, astationary pointer carried by the cylinder and coacting with thecalendar scale, a pointer carried by the cylinder to movecircumferentially therearouml and coacting with the time scale, aslotted member extending radially inward from the adjustable pointer andthrough which the star is observed as it travels in its orbit around theNorth Star, and a sighting tube mounted centrally in the cylinder andthrough which the North Star is observed.

2. An observation instrument comprising a cylindrical member, a pair ofannular disc members surrounding the cylinder, the exposed tace of onemember being graduated into hours and minutes and the exposed face outthe other member into months and days, and means for securing theannular members together after being independently adjusted to thedesired position.

37 An observation instrument comprising a sighting tube through whichthe North Star is observed, a cylindrical device in whicll the tube isrevolvably mounted such device having its axis pointing to the centre ofthe North Stars orbit and adjustable to the daily travel of apredetermined star in its orbit around the North Star, an annular dischaving time graduations therearound and. mounted on the cylindri aldevice, a member having a sighting orifice adjustable concentricallyaround the tube to conform to the varying daily position of suchpredetermined star, and a pointer carried by such member in radialalignment with the orifice to indicate the change in time on anyparticular day to which the device is set.

4:. An observation instrument comprising a base, a sighting tube throughwhich the North Star observed, a cylindrical device mounted to swing ona transverse axis carried by the base and in which the sighting tube ismounted, and having its centre line extending at right angles to thetransverse axis and pointing directly to the centre of the North Starorbit When the North Star is visible through the sighting tube, apointer carried upon the swinging device, and a stationary graduatingquadrant carried by the base with which the pointer coacts.

JAMES STEPHEN.

